Sidney h



(No Model.)

S. H. SHORT.

DYNAMO EiEOTRIO MACHINE. No. 356,667. Patented Jan.25,1887.

H 6/6076 JAM 669x07 w UNITED STATES PATENT 1 OFFICE.

SIDNEY H. SHORT, OF DENVER, COLORADO.

DYNAMO-ELECTRlC MACHINE.

SPECIFICATION forming part of Letters Patent No. 356,667, dated January 25, 1887.

Application filed May 6, 1886. Serial No. 201,331. (No model.)

To aZZ whom it may concern.-

Be it known that I, SIDNEY H. SHORT, of Denver, in the county of Arapahoe and State of Colorado, have invented a new and useful Improvement in Dynamo-Electric Machines and Motors; and I do hereby declare that the following is a full, clear, and exact description of the same.

My invention relates to dynamoelectric machines and motors, and is designed for the purpose of giving a varying quantity of current with a constant electro-motive force.

The invention consists, essentially, of a dynamo-machine in which two complete magnetic systems are combined with one armature, each system having its poles in a position to act upon that armature. One of these magnetic systems acts upon the armature as a series-wound machine, the wire oi" the system being placed in series on the main circuit of the machine. The other magnetic system, which is distinct and separate from the first, has its poles placed so that it will act upon the same armature, but has its wire in shunt with the terminals of the machine.

In the accompanying drawing, the figure represents a plan view of the field-magnets, with the armature in section, and a diagrammatic view of the wires and their connections.

In this drawing, A represents an armature which is substantially triangular in cross-sec:

tion; but it may be any ordinary armature of a dynamo-electric machine, with any kind of winding. The armature is carried on the shaft S, with its commutator G in contact with the brushes 1) b, connected, as usual,with the coils on the armature. The armature revolves be tween the pole-pieces of two independent fieldmagnets, M M. The magnet M is shown as wrapped with coarse wire,one end of the coarse wire being connected to the minus terminal of the machine, and the current passes to the brush 1) at the commutator, through the armature and the other brush, and thence around a field-magnet, M, to the plus terminal, and thence through the lamps L, or other translating device, completing the circuit; By the proper construction and speed of armature a sufficient electro-motive force is produced to light the lamps placed in the multiple arc.

Thus far the machine described is of course a simple series-wound dynamo, with lamps in multiple are, and operates in the ordinary way, and, as is well known, if a number of the lamps L were disconnected, the electro-motive force of the series dynamo would fail, and the remaining lamps would not be lighted because of the reduced current from the coil of the field-magnet M. To remedy this I apply to the same armature a separate and distinct magnetic system. This is sufficiently illustrated in the drawing, and is represented by the horseshoe-magnet M, the pole-pieces of which, 19 p, are arranged in their relation to the armature in the same manner as the poles P P of the field-magnet M. The magnet M I have represented in the figure as wound with finer wire,f, which is in a shunt from the terminals of the machine. It results from this arrangement of the independent systems, in connection with the single armature, that the poles of the field-magnet M will increase in magnetic intensity as the poles of the fieldmagnet N decrease in magnetic intensity. Therefore the electro-motive'force of the terminals of the machine can, by a proper rela tive adjustment of the Ampere turns around M M, be kept constant. If with this adj ustment the magnet M were removed from the machine and the magnet M were left alone to act upon the armature A, its electro-motive force would be at a maximum when the highest resistance is placed between the terminals plus and minus, so that when only one lamp is placed between the terminals the electromotive force will be sufficient to light it. The magnet M will then, if present, be almost wholly out of action, the current being sent through the shunt-coils of the finer wire to ex cite one magnetic system and make the machine give its proper electro-motive force. When, however, the terminals are short-circuited, or more lamps are placed in the multiple are between the terminals, the field-magnet M will increase its activity and the larger current pass through the coarser wire, so that the electro-motive force, which would have fallen if dependent wholly upon the shuntdynamo, is kept 'up by the series dynamo, and the two systems, in their described relation to the same armature, under all circumstances ICO supplement each other and keep up a corn 2. The combination, with an armature, A, 15 of the field-niagnet M, having a pole on each side of the armature, and being wound with coarse wire in series with the armature and line, and a field-magnet, M, having a pole on each side of the armature, but wound with finer wire, and in a shunt taken from the terminals of the machine, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

SIDNEY H. SHORT.

Witnesses:

RODNEY CURTIS, \VILLIAM G. EVANS. 

